SUPPLEMENTARY TEXT:
Portable TV Sets
In the early days of TV sets were physically large but screens were small, and, in fact, the 10-inch version reigned supreme for a long time. As TV reached more people, the demand for a larger screen soon followed and set picture size went up considerably. For a short period of time even this was enough, and projection systems became the vogue.
At present there are in current use portable TV sets and living room sets. These are a.c. - powered and use vacuum-tube circuits. There are also fully portable sets , that is, sets that are not dependent on the a.c. line as a source of power for operation ( although they all can be operated in this fashion, if desired).
The key to fully portable TV set is the transistor and the low-power-consumption CRT. As it is well known the transistor is perfectly capable of full operation at reasonably low supply voltages (about 12 v) and a lot of basic research has gone into development of low-power CRT.
All presently available, fully portable sets are designed to operate either from a 12-volt d.c. power line. Almost all have provisions for operation from a 12-volt automatic storage battery.
With the continued research now being made into micro-miniaturization bulky circuits would be a thing of the past. Then it would be possible to make small-screen portable color sets. Cathode ray tubes may undergo great electrical and mechanical changes and miniature CRT’s of the future may not even look like the present ones with a screen at one end and the electron gun at the other.
COMMENTARY
In fact - фактики олараг, яслиндя
Set picture size - телевизорун шякили тясвир етмя юлчцсц
There are in current use - эениш истифадя олунур
a.c. alternate current - дяйишян ъяряйан
d.c direct current - сабит ъяряйан
These are a.c, powered - онлар дяйишян ъяряйанла
гидаланырлар
Low-power-consumption CRT шаьы енержи сярфиййатлы
електрон трубка
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